by Chris Woodyard, USA TODAY

by Chris Woodyard, USA TODAY

The race is on to see which falls faster: gas prices or Toyota's Prius sales.

Toyota had hoped to sell 250,000 Prius hybrids in its four various configurations this year, an impressive figure that would demonstrate how Americans are embracing the need for fuel savings.

But Toyota's top executive in the U.S., Toyota North America CEO Jim Lentz, says the goal may be endangered. The cause: falling gas prices.

"It'll be a challenge," Lentz said of meeting the goal in an interview with Bloomberg News in New York. "We'll continue to push Prius and Prius family, but if it ends up that demand is less than the sales forecast, that may be adjusted."

What's interesting is the reason he thinks the goal may be hard to attain: falling gas prices. As prices fall, people are less inclined to buy a high-mileage hybrid.

Even though families may hold on to their new car for at least four years, as long as they are typically making payments, buyers apparently still react to whatever the prices are on the pump at the time they buy. Low gas prices hurt Prius just like high gas prices imperil sales of large, fuel-thirsty crossover SUVs and performance cars.

Bloomberg points out that Toyota sold about 236,000 Priuses in the U.S. last year, so its goal this year isn't all that far out of reach. It has four versions: The original hybrid, the plug-in hybrid, the V wagon and the C sporty small car.